The once-pristine snow of Antarctica is becoming increasingly tainted with dirty black carbon coughed out from the engines of tourist ships, according to a new study in the journal Nature Communications.
An international team of scientists recently looked for levels of black carbon, essentially soot, that’s produced through the incomplete burning of fossil fuels, at 28 sites across a 2,000 kilometer (1,242 mile) long strip at the northern tip of Antarctica to the southern Ellsworth Mountains. Their findings showed that levels of black carbon were significantly higher in the snow surrounding research facilities and tourist-landing sites compared to background levels.
The darkening of the snow, in turn, makes it absorb more solar energy and become even more vulnerable to melting, a phenomenon known as the albedo effect. The changes may be subtle to the naked eye, but the gentle darkening of the snow can culminate in some significant impacts. The team estimates that the black carbon is resulting in an extra 23 millimeters (0.9 inches) of equivalent snowmelt each summer, with every single visitor being responsible for the summer melting of roughly 83 tons of snow.
“Burdens of BC [black carbon] deposition varied geographically, but we estimate that premature snowmelt due to the BC footprint of tourism is on the order of dozens to hundreds of tons per visitor,” the study reads.
In decades gone by, Antarctica was home to little more than penguins and a few scientific research outposts, but the continent is seeing an increasing amount of human activity. Around 74,000 tourists visited Antarctica in the 2019–2020 season, a figure that’s up 32 percent from the 2018–2019 season and more than twice the total a decade ago.
Much of the black carbon deposits come from the emissions from fossil fuel-guzzling ships, which is how the vast majority of tourists visit Antarctica. As per the study, the International Association of Antarctica Tour Operators has a growing fleet of 54 vessels, including six large cruise ships, and carried out over 375 departures in the 2019–2020 season.
While the idea of visiting Antarctica as a tourist may be tempting, the researchers argue that their findings show we need to seriously reconsider our relationship with Antarctica. On top of pushing for a faster transition to clean fuel and hybrid or electric ships, the study authors also believe there need to be stricter limits on the number of tourists allowed here each year.
It’s thought that the black carbon footprint per tourist was actually larger a decade ago, before the ban of heavy fuel use in the area and other steps to clean up Antarctica ships, but more needs to be done. If not, the future of Earth’s coldest, windiest, and driest continent won’t be pretty.